Means for refining coal slimes or the like



May 26, 1925. 1,539,746

J. w. KLEINBENTINK MEANS FOR REFINING COAL SLIMES OR THE LIKE Filed Nov. 6, 1923 2;: ve 7a 50 7 a], W: K66 6'71 ezeizl f Patented May 26, 1925.

UNITED STATES PATENT OFFICE.

JAN WILLEM KLEINBENTINK, OF HOENSBROEK, LIMBURG, NETHERLANDS, ASSIGNOR T0 NAAMLQOZE VENNOOTSGHAP VEREENIGDE KOLENMAATSCHAPPIJ EN TER V'OORTZETTING DEB STEENKOLENZAKEN, GEDREVEN DOOR DE N. V. FURNESS KOLENMAATSCHAIPIJ EN HOVEN EN HENNYS HANDELMAATSCHAPPIJ/OF ROT- TERDAM, NETHERLANDS, A COMPANY ORGANIZED UNDER THE LAWS OF THE NETHERLANDS.

MEANS FOR BEFINING COAL SLIMES OR THE LIKE.

Application filed November 6, 1923. Serial No. 673,207.

To all whom itmay com-01%:

Be it known that I, JAN \VlLLEM KLEIN- BENTINK, a subject of the Queen of the Netherlands, residing at Hoensbroek, Limburg, Netherlands, have invented certain new and useful Improvements in Means for Refining Coal Slimes' or the like, of which the following is a specification.

The present invention relates to means for refining coal slimes or the like in such a manner that the slimes are brought into mixed relation with a substance capable of producing froth which when formed entraps coal particles and thus contains coal particles with a lower percentage of ashes than that of the original slimes. The present process is based on the fact that, When finely divided im ure coal held in suspension in a froth- 'orming liquor is brought .into intimate contact with a great number of small air bubbles distributed throughout the liquor, the relatively pure coal particles are entrapped and held by the air bubbles and rise into the layer of froth overlying the surface, whereas the particles having a comparatively high percentage of ashes remaln in the liquor or settle to the bottom thereof.

In accordance with the invention the means for carrying this known method into practice comprise a mixing vat in which the slimes are thoroughly inte mixed with water and with a froth-producing substance and into which air is introduced, in combination with a froth-containing vat in communication with the mixing vat and permitting the froth with the relatively pure coal particles adhering thereto to separate from the particles having a comparatively high percentage of ashes, both vats being also in communication with each other through a second duct by which part of the liquor which is transferred from the mixing vat into the froth-containing vat returns into the mixing vat. By these means an efiicient circulation is procured so that the mixture is repeatedly subjected to the action of the mixing and agitating means, the result being that the relatively pure coal particles ascend into the aerated layer of froth as completely as possible.

The annexcd drawing illustrates diagramn'latically and by way of example only an apparatus in accordance with the present invention, Figure 1 being a vertical sectional view, and Figure 2 a plan View thereof.

The coal slimes, water and a froth-producing substance are continuously admitted into the mixing vat 6 through a pipe a. If desired, however, the froth-producing substance could be introduced through a separate pipe 0. Themixing and agitating apparatus comprises a spindle 01 provided with blades e or wings set in such a manner that, when the spindle 03 rotates in a given direction, the liquor is mixed and agitated and it is transferred through openings 7 near the bottom into the frothing vat g surrounding the mixing vat. In the froth-containing vat g the velocity of flow of the liquor is reduced to suchan extent that the air bubbles and the relatively pure coal particles entrapped thereby rise to the surface, whereas the particles having a comparatively high percentage of ashes settle and are flushed out through a pipe h. Part of the liquid is discharged through an overflow pipe i, the remainder of the liquid returning into the mixing vat I) through holes is so as to be again subjected to the action of the agitating and mixing apparatus and the air bubbles can again entrap and hold the relatively pure coal particles still present. This circulation of the liquor is a typical feature of the present invention and is indicated by arrows in Figure 1.

The froth is removed from the froth-containing receptacle in any suitable manner and may be subjected to subsequent treatment if so desired.

From the drawing it follows that the wall of the mixing vat forms a frustum of an upwardly pointing cone, whereas the wall of the frothing vat forms a co-axial frustum of a cone pointing downwards. This construction has certain advantages, not only as far as the formation of froth is concerned, but also with a view to the easy ascent of the air bubbles to the surface of the liquid in the froth-forming vat.

As far as the operation of the apparatus is concerned, it is innnaterial how the froth is produced. In practice the coal slimes are ordinarily thinned with water and the resulting liquor mixed with air. Obviously, howthe rats could be. disposed side by side or inv descending order.

In the example illustrated the mixing and agitating apparatus simultaneously acts as a pump which efl'ects the required circulation. It will. however be understood that these actions could be etl'ected by means independent the one of the other.' For in stance. the pump could be disposed in the froth-containing vat between the openings f and l'. These and other modifications may be found desirable to meet the requirements of use and they fall within the nature and scope of the invention as expressed in the accompanying claims when broadly eonstrued.

Having now particularly described and ascertained the nature. of my said invention and in what manner the same is to be performed, I declare that what I, claim is In an apparatus for concentrating coal slimes and ores in acordance with the froth flotation process, a froth forming vat, the width of which increases from the bottom to the top, an agitating box within said vat, the width of the box decreasing from the bottom to the top, with the upper edge of the box above the upper edge of the vat, the box being in filOHllllllIllCiltlOl] with the vat through an exit opening near the bottom and an inlet opening above the bottom and below the upper edge of the vat, an agitating meansarranged in the x and rotatable about a vertical axis to force the material in the agitating box through the exit opening into the vat, the inlet opening permitting the return of the material from the vat to the agitating box.

In testimony whereof I afiix my signature.

J AN \VILLEM KLEINBENTINK. 

